The wireless packet networks of the mobile communication network allow data transmission between a server and a client, but if there is no data transmission for a certain period of time, the mobile communication network provider disconnects the wireless link between the server and the client for efficient use of the limited resources of the wireless telecommunication network while keeping the session of the upper layer protocol. This may cause problems such as data transmission delay for IP-Relay or IP-CTS services where a real-time text data transmission is critical for effective communication with deaf and hard-of-hearing individuals. Accordingly, the object of the present invention is to eliminate such delay, caused by the disconnection configuration of the wireless packet networks, for real-time text data transmission by IP-Relay or IP-CTS services in order to provide better service and customer satisfaction.
The use of IP-Relay or IP-CTS services has increased due to a growing population of elderly people with hard of hearing as well as people with congenital or acquired hearing loss, and there is a growing need for the services to be provided to mobile communications devices such as cellular phones or smart phones where such services are limited to a fixed IP terminal of a computer under the wired or WiFi packet network environment. How IP-Relay or IP-CTS service works is as follows. First, a Call Agent (“CA”) transcribes and converts what a hearing-capable user says into text data, and transmits the text data to a hearing-impaired user via IP networks. However, wireless packet networks have limited wireless resources and, they utilize a wireless resource saving feature to release wireless resources while maintaining the upper protocol session if there have been no data transmissions between a server and a client for a pre-set period of time (“T-time period”). Consequently, once the wireless resource saving feature is triggered to release wireless resources while maintaining the upper protocol session, there is a transmission delay and real-time transmission cannot be guaranteed if the server or the client tries to transmit data again because it takes time to re-allocate wireless resources to the link between the server and the client.
FIG. 1 shows a conventional process of text data transmission from a CA to a user using IP-Relay or IP-CTS via a wireless packet network.
Text data is transcribed and generated from the voice of the hearing-capable user and the CA transmits the text data to the hearing-impaired user as part of IP-Relay or IP-CTS services. In FIG. 1, the text data (n, n+1, n+2) generated by a CA is transferred to a user without delay because the transmission is being done by the active wireless connection. However, when the hearing-impaired user speaks and the hearing-capable user listens to the hearing-impaired user, text data is not generated by the CA and there is no data transmission through the wireless packet network. If there have been no data transmissions for a time exceeding the T-time through the wireless packet network, the wireless resources are released. Once the wireless resources are released and if the hearing-capable user begins to speak and the CA converts what he says into text data (n+4, n+5) and requests transmission of the text data through the wireless packet network, then the wireless packet network will begin to reallocate wireless resources to the connection between the two users in an attempt to transmit the text data (n+4, n+5). Thus, it takes time for the wireless connection to be completed and for the text data transmission to become ready again, and the text data (n+4, n+5) transmission is delayed as much as T-alive. The text data (n+6, n+7, n+8, n+9) generated after the wireless session is re-connected is transmitted without delay and transmitted almost simultaneously with the previous text data (n+4, n+5). Due to the wireless resource saving feature of the mobile packet network, conventional IP-Relay or IP-CTS service fails to maintain real time transmission of text data transcribed from voice data.
Accordingly, to solve the above problems, a need for a text relay service communication system and method for a real-time transmission of transcribed voice data via a wireless packet network has been present for a long time considering the expansive demands in the everyday life. This invention is directed to solve these problems and satisfy the long-felt need.